It is known to use cooling elements to protect equipment used in various steel industry processes. Such equipment may need to operate in extreme heat-flux conditions. Conventional cooling elements typically comprise a plurality of tubes or pipes having water running through them and which are coupled together to form the cooling elements. Such conventional tubes may for example be 2.5 inch inner diameter (“ID”) cylindrical tubes having maximum water velocities through the tubes of about six (6) to seven (7) feet per second. The high heat flux conditions in which these tubes may operate make it desirable to have higher heat transfer rates and higher water velocities than the conventional 2.5 inch ID tubes can deliver. It is also desirable to be able to choose to fabricate the tubes and resulting elements from any suitable material and using any method of fabrication suitable for the material being used.